Swift version: 5.6
There are two ways to center one
UIView inside another, depending on whether you use Auto Layout.
If you don’t use Auto Layout, it’s only one line of code:
childView.center = parentView.center
That sets the position once, so it won’t update when your user rotates their device or if they use something like Slide Over to change the size of your app.
If you’re using Auto Layout, you can center your child view inside its parent like this:
childView.centerXAnchor.constraint(equalTo: parentView.centerXAnchor).isActive = true childView.centerYAnchor.constraint(equalTo: parentView.centerYAnchor).isActive = true
Those constraints will automatically update as the available space changes.
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Available from iOS 3.2
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
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